#' @param input [data.table::data.table]\cr
#' `data.table` with columns `name` (`character`), `train` (`character`), `predict` (`character`).
#' Sets the `$input` slot, see [PipeOp][mlr3pipelines::PipeOp].
#' @param output [data.table::data.table]\cr
#' `data.table` with columns `name` (`character`), `train` (`character`), `predict` (`character`).
#' Sets the `$output` slot, see [PipeOp][mlr3pipelines::PipeOp].
